The present invention relates to an organic EL (Electroluminescent) display device in which a technique is employed for preventing deterioration of the light emitting material thereof by ambient light.
In an active-matrix-type organic EL display device, respective gate signal lines, which extend in the x direction and are arranged in parallel in the y direction, and respective drain signal lines, which extend in the y direction and are arranged in parallel in the x direction, are formed on one surface of a substrate, and regions surrounded by the gate signal lines and the drain signal lines constitute pixel regions. Each pixel region is provided with a switching element, which is turned on in response to a scanning signal from the gate signal line, and a pixel electrode to which a video signal is supplied from the drain signal line through the switching element.
The pixel electrode is configured such that a light emitting material layer is interposed between the pixel electrode and a counter electrode, and the light emitting material layer emits light in response to an electric current which flows between the pixel electrode and the counter electrode. Here, the counter electrode is, for example, formed over respective pixel regions in common, and a signal having a voltage which becomes a reference with respect to the video signal is applied to the counter electrode. Then, by forming at least either one of the pixel electrode and the counter electrode as a light-transmitting conductive layer, light from the light emitting material layer can be allowed to pass out to this one electrode side, from which the light reaches the eyes of an observer.
The following publications by the inventors of the present patent application disclose examples of this type of EL display device.    Patent Document 1: Japanese Unexamined Patent Publication 1996-321381.    Patent Document 2: Japanese Unexamined Patent Publication 2000-223271.